Prognostic Value of Concanavalin A Reactivity of Primary Human Breast Cancer Cells1

A prospective, double-blind study was carried out to deter mine whether reactivity with concanavalin A (Con A) of human breast cancer cells was related to early disease recurrence. Mammary epithelial cells were isolated from 138 primary hu man breast cancers. The cells were placed in culture, and their reactivity with Con A was determined with a hemadsorption assay in which human erythrocytes treated with various con centrations of Con A were incubated with the test (mammary epithelial) cells in situ. The Con A half-maximum value was determined as the concentration of Con A at which approxi mately 50% of the test cells adsorbed erythrocytes. Con A reactivity of the tumors was classified as high or low (halfmaximum value <30 or >30 /xg/ml, respectively). Patients were followed for 2 to 60 months after primary surgery (median, 22 months). Those patients having tumors that were highly reactive with Con A were at significantly greater risk of devel oping early recurrence of their cancers than were those pa tients with low-reactivity tumors. No correlation was found between Con A reactivity and the age of the patients, their menopausal status, the number of axillary lymph nodes infil trated with tumor, the estrogen receptor content of the tumor, or the clinical stage of the disease. These data show that Con A reactivity is an independent discriminator for identifying those breast cancer patients who are at high risk of developing early recurrent disease.